The present invention relates to a hydraulically controlled brake comprising at least one friction element, for example a pad where a disc brake is concerned, designed to be clamped against a rotating track under the thrust of a piston mounted to slide in a cylinder body, in response to a generation of pressure in a control chamber filled with hydraulic fluid and defined by the piston in the cylinder body.
The invention relates more particularly to such a brake, in which the piston comprises a cup-shaped piece which has a cylindrical side wall engaged in the cylinder body and a bottom adjacent to the control chamber.
The invention relates even more particularly to such a brake, in which means are provided to prevent an excessive rise in temperature of the hydraulic fluid and consist of a cylindrical core which is made of mechanically resistant and thermally insulating material and which is engaged in the cup.
In general, the means for fitting the core into the cup make use of an effect which involves engaging the core into the cup by force, thus increasing the production cost.
The subject of the present invention is a hydraulically controlled brake of the type mentioned above, in which the construction of the piston is particularly simple and convenient, at the same time with a reduced cost price and excellent effectiveness against the risks of excessive heat of the hydraulic fluid.